Search Results

Search found 4 results on 1 pages for 'pycairo'.

Page 1/1 | 1 

• How can I "best fit" an arbitrary cairo (pycairo) path?

  - by Daniel Straight

  It seems like given the information in stroke_extents() and the translate(x, y) and scale(x, y) functions, I should be able to take any arbitrary cairo (I'm using pycairo) path and "best fit" it. In other words, center it and expand it to fill the available space. Before drawing the path, I have scaled the canvas such that the origin is the lower left corner, up is y+, right is x+, and the height and width are both 1. Given these conditions, this code seems to correctly scale the path: # cr is the canvas extents = cr.stroke_extents() x_size = abs(extents[0]) + abs(extents[2]) y_size = abs(extents[1]) + abs(extents[3]) cr.scale(1.0 / x_size, 1.0 / y_size) I cannot for the life of me figure out the translating though. Is there a simpler approach? How can I "best fit" a cairo path on its canvas? Please ask for clarification if anything is unclear in this question.

  Read the article

• How to keep text inside a circle using Cairo?

  - by miguelrios

  I a drawing a graph using Cairo (pycairo specifically) and I need to know how can I draw text inside a circle without overlapping it, by keeping it inside the bounds of the circle. I have this simple code snippet that draws a letter "a" inside the circle: ''' Created on May 8, 2010 @author: mrios ''' import cairo, math WIDTH, HEIGHT = 1000, 1000 #surface = cairo.PDFSurface ("/Users/mrios/Desktop/exampleplaces.pdf", WIDTH, HEIGHT) surface = cairo.ImageSurface (cairo.FORMAT_ARGB32, WIDTH, HEIGHT) ctx = cairo.Context (surface) ctx.scale (WIDTH/1.0, HEIGHT/1.0) # Normalizing the canvas ctx.rectangle(0, 0, 1, 1) # Rectangle(x0, y0, x1, y1) ctx.set_source_rgb(255,255,255) ctx.fill() ctx.arc(0.5, 0.5, .4, 0, 2*math.pi) ctx.set_source_rgb(0,0,0) ctx.set_line_width(0.03) ctx.stroke() ctx.arc(0.5, 0.5, .4, 0, 2*math.pi) ctx.set_source_rgb(0,0,0) ctx.set_line_width(0.01) ctx.set_source_rgb(255,0,255) ctx.fill() ctx.set_source_rgb(0,0,0) ctx.select_font_face("Georgia", cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD) ctx.set_font_size(1.0) x_bearing, y_bearing, width, height = ctx.text_extents("a")[:4] print ctx.text_extents("a")[:4] ctx.move_to(0.5 - width / 2 - x_bearing, 0.5 - height / 2 - y_bearing) ctx.show_text("a") surface.write_to_png ("/Users/mrios/Desktop/node.png") # Output to PNG The problem is that my labels have variable amount of characters (with a limit of 20) and I need to set the size of the font dynamically. It must fit inside the circle, no matter the size of the circle nor the size of the label. Also, every label has one line of text, no spaces, no line breaks. Any suggestion?

  Read the article

• Drawing a clamped uniform cubic B-spline using Cairo

  - by Tamás

  I have a bunch of coordinates which are the control points of a clamped uniform cubic B-spline on the 2D plane. I would like to draw this curve using Cairo calls (in Python, using Cairo's Python bindings), but as far as I know, Cairo supports Bézier curves only. I also know that the segments of a B-spline between two control points can be drawn using Bézier curves, but I can't find the exact formulae anywhere. Given the coordinates of the control points, how can I derive the control points of the corresponding Bézier curves? Is there any efficient algorithm for that?

  Read the article

• How to return an image in an HTTP response with CherryPy

  - by colinmarc

  I have code which generates a Cairo ImageSurface, and I expose it like so: def preview(...): surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height) ... cherrypy.response.headers['Content-Type'] = "image/png" return surface.get_data() preview.exposed = True This doesn't work (browsers report that the image has errors). I've tested that surface.write_to_png('test.png') works, but I'm not sure what to dump the data into to return it. I'm guessing some file-like object? According to the pycairo documentation, get_data() returns a buffer. I've also now tried: tempf = os.tmpfile() surface.write_to_png(tempf) return tempf Also, is it better to create and hold this image in memory (like I'm trying to do) or write it to disk as a temp file and serve it from there? I only need the image once, then it can be discarded.

  Read the article

1